Electric circuit breaker



April 23, 1935. J. PERlNo ELECTRIC CIRCUIT BREAKER Filed Dec. 22, 1955Inventor:

Jules F M110,

`His Atborneg.

Patented AApr. 23, `1935 e. y 'n l UNITED STATES rPATlszNT orrics JulesPerino, Philadelphia, Pa., assigner to General Electric Company, acorporation of New 'Yorkf Application December 2 2, 1933, Serial No.103,570

4 claims. (ci. zoo-15o) 'y f i My invention relates to electric circuitbreakable contacts 2 and 3 as by inner insulating cyl- 1 ers, moreparticularly to electric circuit breakinders I0 and II ntted to theinner wall of the 5 ers of the so-called oil-blast explosion-chamber pot1 and by an insulating throat bushing .I2 'gf type wherein an initialpressure generating arc having a central ilared opening I3 for receiving5 is ,formed for causing the circuit-interrupting oil the movablecontact l." The insulating cylin- 5 blast, and has for its principalobject the provision derS lilk and ll Serve t niOunt and pOSitiOn en ofsimplified and improved contact structure for insulating diSk il 0nwhich the intermediate eOncircuit breakers of the aforesaid type. tact 2is mounted. The insulating disk Il is pro- My invention/will be morefully set forth in Vided With apertures I4' extending tliiOugli the 10the renewing description referring to the acsame and interconnectingupperk and lower por- 10 companying drawing, and the features of noveltytiOnS 0f the eXplO'SlQn Chamber fOr apurpOSe preS- which characterize myinvention wiii be pointed ently described. The intermediate contact 2 isout with particularity in the claims annexed to pOSitiOned in aCentrally disposed aperture l5 in and forming a part oi thisspecication. the insulating disk.

c Referring more particularly to the drawing, 'I'he throat bushing I2 issecured in position by 1.5 the single iigure thereof is anelevationalview in a Spacing nut I6 and lock nut I1 which are cross section of onepole o! a circuit breaker of threaded directly 0n the insulatingbushing. The the oil-blast explosion-chamber type embodying insulatingCylinder ll extends as at Il Over the the present invention, inner edgeofthe explosion pot throat flange 9 y The explosion chamber contactstructure i1- and a suitable gasket I8 is positioned between the 20lustrated constitutes one pole of a circuit breaker byerlinging iiange0f the threat bushing l2 and of a, well-known type wherein two similarexplothe insulation II. The exterior ot the pot 1 is sion chambercontactstructures, comprising the sultalily insulated es by Sleeve-likeinsulating two poles of the switch, are immersed in an insu- Cylinder i9SuppOrted by an insulating flange 20 lating liquid as cil dnd areinterconnected in which is in turn secured to the pot 1 by a nut 2|. 25l closed circuit position by a conducting bridging The upper butt eenttl eOlnpriSeS a eylinmember which is vertically movable within the dricalguide pOltiOn 22 Which i5 Slidably mounted insulating liquid withrespect, i-,o lche explosion on a bolt 23 secured to the adapter 5 andresilchamber structure. In the present instance the iently biased. aS byCoil Spring 2l, towards the expicsicn chamber ccntnci, structurecomprises lower position illustrated. The guide bo1t'23 is 30 a buttcontact I, an intermediate or floating conprOvided With an insulatingSleeve 25 and downtact 2 and a. mcvnb1e tubular contact 3 which is wardmovement of the butt contact I is limited carried by the aforesaidbridging member. In the by a SliOulder 22' 0f the guide Dertien 22 whichclosed circuit position the 'intermediate contact iS arranged to abutthe corresponding Shoulder 2 is in butt contact engagement withcenter-,ts 23' at the lower end of the bolt 23. The actual 35 l and 3 soas to complete the circuit between the Contact making and arcing surfaceof the ybutt lead-in conductor 4 and the bridging member, contact I isformed by a replaceable cap 26 se- The explosion chamber structurecomprises an Cured aS by Screw-threaded engagement at 2l t0 adapter 5and a connecting member 6 to which the portion 22 and composed oi asuitable conthe adapter is connected so that the lend-in ccnducting andarc-'resisting metal. The electrical 40 ductor. l is electr-lennyconnected to the adapter 5 .connection between the butt contact I andthe and rigidly mounted with respect thereto. The adapter 5 is providedby a plurality of exible adapter 5 in turn is connected to and supportsconductors 28 which directly conduct current a steel cylindrical member1 comprising an exfrom theadapter 5 to the contact AI thereby proplosionchamber pot. The pot 1, which is ccntecting the biasing spring 24 fromoverheating. f..

structed to withstand high bursting pressures, is The intermediatecontact 2 is simply and eblnconnected at its upper inner edge to theadapter paetly arranged Within the ekplOSiOn chamber as byscrew-threaded engagement indicated at-a and, as previously described,is insulated with and at its lower edge is provided with aninwardrespect to the pot 1 by the insulating disk il 5o ly extendingannular flange l forming generally which likewise serves as a supportfor the inter- 50 the throat or exhaust of the explosion chamber mediatecontact. The intermediate contact comthrough which the movable tubularcontact 2 is prisesja short tubular member 29 of conducting operated.material having connected thereto at opposite The explosion chamber pot1 is suitably insuends butt contact portions I0 and II for coastinglated with respect tothe intermediate and movwith the contacts I and I.,respectively. The 55 butt-contact portions 30 and 3| are convenientlyformed by disk-like portions having threaded extensions or studs 3U' and3l respectively arranged to engage corresponding threaded portions inthe interior ot the tube 29 as illustrated. When so secured in position,the contact portions are locked with respect to tube 29 by pins 32.

A coil spring 33 seated at one end in a recess 34 in the insulating diskI4 and at its other end in a retainer 35 normally biases theintermediate contact to the lower position illustrated where it is heldagainst further movement by the engagement of the contact portion 30with the insulating disk I4. An insulating sleeve 33 secured to the diskI4 surrounds and protects the spring 33. As in the previous instance,the contact portions 30 and 3|, and likewise the removable contact tip3' of the tubular contact, are composed of.

suitable arc-resisting contact metal.

Referring more particularly to the operation oi' the device, the closingof the circuit is effected by elevation of the tn bular contact 3 whichrst engages contact portion3| oi the intermediate contact and elevatesthe intermediate contact against the bias of spring 33 into engagementwith butt contact I. Overtravel of the bridging member is provided forby reason of the resiliently mounted butt contact I.

Opening of the circuit is eiected by lowering o! the tubular contact 3,the contacts continuing in following engagement until the butt contact Ireaches its lower limit of travel, at which time separation of the buttcontact and intermediate contact 2 occurs. The resulting arc within theexplosion chamber, which is illled with oil or other suitable insulatingliquid, generates a high pressure within the chamber by reason ofdecomposition of some of thevinsulating liquid by the arc. Continuedlowering of the contact3 results in separation of the same from theintermediate contact when the latter contact reaches its lower limit oftravel, resulting in a second arc in series with the rst or pressuregenerating are between the contacts 2 and 3. As the tubular contact 3passes through the throat of the explosion chamber the aforesaidpressure causes a blast of oil from the chamber through the second arcand into the tubular contact to exhaust extericrly of the explosionchamber thereby extinguishing said arc and interrupting the circuit.

After circuit interruption the explosion chamber rells with oil from themain circuit breaker tank, the adapter 5, which forms the top wall ofthe explosion chamber, being provided with an aperture 31 for permittingescape of accumulated gas and serving to limit excessive pressure. Theaccumulation of gas generated within the explosion chamber is localizedto a considerable extent at the upper part of the explosion chamber byreason of the insulating disk I4, the apertures I4 serving generally totransmit pressure to the lower part of the chamber so that a blast ofoil rather than gas is obtained for interruption oi' the arc.

It should be understood that my invention is not limited to speciilcIdetails of construction and arrangement thereof herein illustrated, andthat changes and modincations may occur to one skilled in the artwithout departing from the spirit of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. An electric circuit breaker of the oil-blast explosion-chamber typecomprising relatively movable contacts including an intermediatecontact, said intermediate contact comprising a tubular conductingmember, insulating structure in which said tubular member is slidablymounted, and butt contact arcing portions detachably coneected to theopposite ends of said tubular mem- 2. An electric circuit breaker ot theoil-blast explosion-chamber type comprising relatively .movable contactsincluding an intermediate contact, said intermediate contact comprisinga tubular conducting member, and disk-like butt contact portions atopposite ends ot said tubular member having screw-threadedl studportions extending into and engaging said tubular member forelectrically and mechanically connecting said butt contact portionsthereto.

3. An electric circuit breaker of the oil-blast explosion-chamber typecomprising relatively movable contacts including an intermediatecontact, means forming an explosion chamber in which said contactscoact, an insulating disk mounted in said chamber and supporting saidintermediate contact, said intermediate contact comprising a cylindricalconducting member slidably mounted in said insulating disk and disklikebutt contact portions secured and electrical- 1y connected to oppositeends of said cylindrical member, and means biasing said cylindricalmember in a direction longitudinally thereof, one of said disk-like buttcontact portions coacting with said insulating disk for limitingmovement of said intermediate contact.

4. An electric circuit breaker of the oil-blast explosion-chamber typecomprising relatively movable contacts including an intermediatecontact, means forming an explosion chamber in which said contactscoact, an insulating disk disposed withln said chamber and dividing thesame into upper and lower portions. said insulating disk havingapertures therein including an aperture for receiving said intermediatecontact, said intermediate contact comprising a cylindrical conductingmember slidably mounted in said lastnamed aperture, disk-like buttcontact portions secured and electrically connected to the opposite endso! said cylindrical member. a spring interposed between said insulatingdisk and one of said butt contact portions for biasing said intermediatecontact in a direction longitudinally thereof, the other of said buttcontact portions engaging said insulating disk for limiting movement ofsaid intermediate contact, and an insulating sleeve depending from Isaidinsulating disk and surrounding said spring.

JULES PERINO.

